In 1999, Robert Greubel and Stephen Forsey of Greubel Forsey began working together with the premise that all had not yet been invented in mechanical watchmaking, particularly with reference to the tourbillon’s use in wristwatches. They devoted years of research and development to devise new tourbillon systems for the 21st century, which have captured chronometry awards as well as the hearts and imaginations of mechanical watchmaking devotees worldwide.

Please explain the concept behind the tourbillon for those who may not be familiar with it.

The first single-axis tourbillon was invented for pocket watches in order to overcome accuracy problems associated with gravity, lubrication, and materials issues. The tourbillon averages for gravity-induced errors on the balance wheel oscillator by continually rotating the regulating system. This was particularly effective with the pocket watch because its balance was usually in a vertical position.

Since its introduction at the beginning of the 19th century, the tourbillon provided a very high level of precision in mechanical pocket watches. When watchmakers first succeeded in miniaturizing the single-axis tourbillon some 70 years ago, they hoped to obtain similar improvements in timekeeping performance, but, perhaps partly due to the technical challenges of miniaturizing the mechanism, there were no further developments of the tourbillon system in the wristwatch until the turn of the 21st century.

What is the purpose of putting a tourbillon in a wristwatch that constantly changes position?

Bearing in mind that the tourbillon was originally designed for the pocket watch, we realized that its application for the specific conditions of the wristwatch had not been seriously studied. So, we decided to investigate the subject and this led to inventing truly new tourbillon solutions to suit the specific requirements of the wristwatch.

Greubel Forsey Tourbillon 24 Secondes Contemporain

The fundamental research carried out before the official launch of Greubel Forsey showed us that with the balance wheel inclined in the tourbillon system, we could seek improved timekeeping performance especially in stabilized positions (such as when the wristwatch is removed at night). The balance wheel oscillator could be of a larger diameter than the thickness of the movement promising more stable performance and the inclination of the interior cage enabled the oscillator to avoid unfavorable horizontal and vertical positions in a way that was impossible with existing systems featuring a single-axis cage or a 90° angle between their cages.

After four and a half years of intensive work, Greubel Forsey presented the first Double Tourbillon 30° wristwatch with the completely new system of a one-minute cage inclined at 30° and rotating within a second exterior four-minute cage. This was followed in 2005 with the first Quadruple Tourbillon wristwatch, and in 2006 with the first rapidly rotating inclined single-cage tourbillon in the 24-Second Tourbillon wristwatch.

What do you say to those who question whether tourbillons actually improve precision in a wristwatch?

For Robert and I, the major challenge from the beginning of Greubel Forsey was to investigate and prove or disprove if the tourbillon in a wristwatch could really improve timekeeping performance. Solid proof of performance and reliability for regular use was the highest score for precision and first position attained with our Double Tourbillon 30° Technique (DTT30) at the 2011 International Chronometry Competition launched by the Museum of Horology in Le Locle, Switzerland, completed in October after 45 days of rigorous testing and exposure to magnetism and shocks. The DTT30 scored 915 points out of a possible 1,000 to claim first place both in the tourbillon category and the highest score of the overall competition. The best performing non-tourbillon timepiece achieved 764 points.

How did you approach advancing a centuries-old concept for the modern age? Is there still room to push the envelope further?

To go beyond what was the accepted technology, it was necessary to look again with a fresh perspective at the history of the tourbillon. Then we had to refuse to accept that everything had already been invented in the field of mechanical horology after more than 400 years of highly inventive watchmakers—could we open new avenues and create previously unexplored and unimagined solutions?

Greubel Forsey GMT

The constant challenge of working with the tourbillon for the wristwatch is in mastering the compact size and the high number of components required to achieve high precision and performance. Solutions lie in both the architecture and technicalities of the mechanism. There are also aesthetics to consider as the decoration and fine finish of our timepieces is of paramount importance at Greubel Forsey. Hundreds of hours of hand finishing are necessary for each movement and every minute detail is considered—such as internal angles and flat black polishing on steel bridges. Also, an individual component may look aesthetically acceptable on its own, but in the context of the whole movement, if it doesn’t contribute to the overall harmony of the creation, it must be rejected.

We still have many ideas, but to develop new ideas always takes time, and so we must be patient in order to allow us to complete each step of our research. There are also other complications that we want to explore in our own specific way, such as the new GMT, which shows that each Greubel Forsey timepiece represents the spirit of our passion with an in-depth approach to the function and display of each mechanism and complication.